This invention relates to an apparatus for stripping insulation from the end of an insulated wire.
A wire stripping apparatus having a pair of opposed blades is known. In a typical wire stripping apparatus, the blades are provided at each one end of pivotable arms so that opposed cutting edges of the blades are movable toward and away from one another. According to the apparatus comprising pivotable arms, a lengthwise space that accommodates the pivotable arms is required. This may results in a bulky apparatus.
In addition, with the construction having pivotable arms, the cutting edges are cut into insulation of a wire by swinging movement of the arms so that the blades move through an arc. This can lead to uneven tearing of insulation and skiving or nicking of a wire core during subsequent strip.
A typical stripping apparatus of the prior art comprises opposed V-shaped blades as shown in FIG. 5(B). With this configuration, the wire will skive or bent due to the unbalanced forces acting of the opposite sides of the wire. This and other disadvantages of the conventional V-shaped blades are described in U.S. Pat. No. 4,528,741 to Emerson, incorporated herein by reference. The problem that the stripping operation may result in damage to the wire core become acute as the diameter of the wire decreases, as extremely fine insulated wire is difficult to handle, and the thickness of the insulation becomes so small that damage to the core by the stripping tool becomes almost unavoidable.
Next, the stripped insulation removed from the wire end and cutting dust or cutting residue may cling to the cutting edges by an electrostatic force. Adhesion of the same to the cutting edges can lead to cutting or nicking of the wire core during the next stripping operation. In addition, if a number of the stripped insulation portions removed spread out on a floor, cleaning of the floor is required.
Next, the wire core is comprised of generally a bundle of multiple fine strands. Twist of the exposed strands may be required to prevent the bundle of strands from coming apart. Japanese utility model publication No. 5-78122 discloses means for twisting the wire core in which insulation is cut and remains about wire core without removing. The remain insulation is sandwiched between opposite friction plates, followed by moving the opposite plates toward opposite direction one another. In accordance with the disclosure, another means for twisting the wire core is required besides the stripping means.
From the foregoing, the present invention seeks to preclude above disadvantages.
An object of the present invention is to provide a compact stripping apparatus without pivotable arms.
Another object of the present invention is to provide accurate, reliable stripping apparatus that is capable of stripping insulation from a wire without damage to a wire core.
Another object of the present invention is to collect stripped insulation properly and to prevent cutting dust from clinging to cutting edges.
Another object of the present invention is to twist exposed strands during the stripping operation.
There is provided an apparatus for stripping insulation from a wire that comprises a cutter mechanism and a cutter holder for carrying the cutter mechanism. The cutter mechanism has opposite cutting edges that are movable relatively toward and away from one another other perpendicular to the length of the wire. The cutter holder is reciprocally movable along the length of said wire and revolvable about an axis that passes through the wire. The opposite cutting edges move toward to each other to cut into an insulation portion of the wire, followed by revolving the cutter holder about said axis and moving the cutter holder away from an end of the wire to remove the insulation from the wire.
According to the above construction, if a wire core is comprised of a bundle of multiple fine strands, the strands are twisted by the revolving and away movements of the cutter holder.
Advantageously, the apparatus further comprises collecting means for collecting stripped insulation removed from the wire end and cutting dust or residue that may cling to the cutting edges of blades. More preferably, the collecting means comprises an elongate hollow member extending in the length of the wire, more specifically in the axis that passes through the extending wire. One end of the member faces the end of the wire and the other end of the member communicates with vacuum or suction means so that the stripped insulation and dust or residue are positively and forcibly collected via the elongate member.
Advantageously, the cutter mechanism comprises opposed cutter means. One of opposed cutter means comprises a first and a second blades, and the other of opposed cutter means comprises a third and a fourth blades. Each blade has a flat surface on one side of said blade, and a beveled surface on the opposite side of the blade intersecting the flat surface to define the cutting edge, and the cutting edge extends at an angle across the blade. The cutting edge of the blades of each the cutter means form a V-shaped notch, the V-shaped notches of the pair of cutters face each other to form a wire receiving portion. The flat surfaces of the four blades lie generally in a common plane so that the cutting edges of four blades are arranged in the same plane. The beveled surfaces of the first and third blades are opposite to each other and both face in one direction relative to the plane. The beveled surfaces of the second and fourth blades are opposite to each other and both face in the opposite direction relative to the plane. The above construction of four blades is advantageously adapted for twisting the wire core comprising strands when removing the insulation.